[IPV4] fib: fix route replacement, fib_info is shared

fib_info can be shared by many route prefixes but we don't want
duplicate alternative routes for a prefix+tos+priority. Last change
was not correct to check fib_treeref because it accounts usage from
other prefixes. Additionally, avoid replacement without error if new
route is same, as Joonwoo Park suggests.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Anastasov 2008-01-28 21:14:10 -08:00 committed by David S. Miller
parent ec9dbb1c3e
commit c18865f392

View file

@ -424,19 +424,43 @@ static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
if (fa && fa->fa_tos == tos &&
fa->fa_info->fib_priority == fi->fib_priority) {
struct fib_alias *fa_orig;
struct fib_alias *fa_first, *fa_match;
err = -EEXIST;
if (cfg->fc_nlflags & NLM_F_EXCL)
goto out;
/* We have 2 goals:
* 1. Find exact match for type, scope, fib_info to avoid
* duplicate routes
* 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
*/
fa_match = NULL;
fa_first = fa;
fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
if (fa->fa_tos != tos)
break;
if (fa->fa_info->fib_priority != fi->fib_priority)
break;
if (fa->fa_type == cfg->fc_type &&
fa->fa_scope == cfg->fc_scope &&
fa->fa_info == fi) {
fa_match = fa;
break;
}
}
if (cfg->fc_nlflags & NLM_F_REPLACE) {
struct fib_info *fi_drop;
u8 state;
if (fi->fib_treeref > 1)
fa = fa_first;
if (fa_match) {
if (fa == fa_match)
err = 0;
goto out;
}
write_lock_bh(&fib_hash_lock);
fi_drop = fa->fa_info;
fa->fa_info = fi;
@ -459,20 +483,11 @@ static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
* uses the same scope, type, and nexthop
* information.
*/
fa_orig = fa;
fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
if (fa->fa_tos != tos)
break;
if (fa->fa_info->fib_priority != fi->fib_priority)
break;
if (fa->fa_type == cfg->fc_type &&
fa->fa_scope == cfg->fc_scope &&
fa->fa_info == fi)
goto out;
}
if (fa_match)
goto out;
if (!(cfg->fc_nlflags & NLM_F_APPEND))
fa = fa_orig;
fa = fa_first;
}
err = -ENOENT;